1. Field of the Invention
The present invention relates to an improved printing sheet having good ink adhesive properties, sheet running properties, anti-blocking properties, etc., and more particularly relates to an improved printing sheet having good adhesive properties when used with ultraviolet-curable ink (hereinafter, "ultraviolet-curable ink" is referred to as "UV ink").
2. Prior Art
In recent years, a diversification of printed products requires printing on a wider variety of materials in sheets, for example, papers, synthetic papers, thermoplastic resin films, metallic foils, metallized sheets, etc. These printed items are printed by methods such as by offset printing, gravure, flexography, screen process printing and letterpress printing. In these printing methods, a method which uses UV ink has recently become popular because UV inks cure rapidly, and the printing method which uses UV ink is of superior handling. At present, there is a great demand for flat, sheet-like items.
In printing methods which use UV ink, the printing sheet requires, in particular, the property of adhering well to cured UV ink. Additionally, general required properties such as sheet running properties, anti-blocking properties, producing uniform spread of the ink over the surface of the sheet, as well as antistatic properties.
However, the above materials formed in sheets, especially films of thermoplastic resin, will not sufficiently adhere with UV ink after printing and curing. Accordingly the printed and cured UV ink has a problem in that the printed and cured UV ink separates from the materials formed in a sheet.
Therefore, a printing sheet which has superior adhesion with the UV ink is required.